An SDN (Software Defined Networking) architecture based on an idea that control and forwarding are separated is a novel network switching model, which plays a favorable promotion role in network innovation and development, and key components of the SDN architecture include an OpenFlow switch and a controller. Message exchange and information transmission are completed between the controller and the OpenFlow switch through a control channel of an OpenFlow protocol specification. The controller implements management and control functions by using a network-wide view, to generate a forwarding flow table for the OpenFlow switch. The OpenFlow switch forwards a data packet according to the flow table, and a flow entry mainly includes match field(s) and instruction(s), and the like. However, live networks have been deployed with a large quantity of conventional forwarding devices, while the SDN/OpenFlow is an emerging network architecture and forwarding model after all. Therefore, how to be compatible with these conventional network forwarding devices in support of conventional forwarding models is a challenge SDN/OpenFlow confronts.
To be compatible with these network forwarding devices in support of conventional forwarding models, ONF (Open Networking Foundation) defines a NDM (Negotiable Datapath Model) and TTP (Table Typing Pattern) specification and description language, and the TTP is the first stage of the NDM in support of an existing OpenFlow protocol version, for example, OpenFlow-Switch 1.x. The NDM/TTP defines a frame. Based on the frame, vendors are allowed to define a variety of forwarding models on the basis of an actual application requirement and an existing chip architecture. Each model may relate to a plurality of tables, match different fields, and perform different actions based on search results. An existing chip is based on, where both matched fields and performed actions are limited. Therefore, the NDM/TTP describes a limited subset of a forwarding capability of the OpenFlow switch defined in the OpenFlow protocol specification.
To some extent, the NDM/TTP resolves a compatibility problem between the OpenFlow and the conventional forwarding models. However, when parameters required for existing forwarding logic and forwarding tables are forwarding parameters that are not defined in the OpenFlow protocol specification, the OpenFlow protocol requires to be extended to provide support in the prior art. A standard promotion requires to be performed for a long time, and whenever a new forwarding parameter that is not defined in the OpenFlow specification requires to be added, one or more corresponding standard promotions require to be performed. It is rather time-consuming, laborious, and complex to extend these forwarding parameters to the OpenFlow protocol specification, delaying and affecting a promotion and development speed of the SDN/OpenFlow technology to some extent.